libwebsockets

ss: UNREACHABLE: set ordinal in state cb b0 if due to DNS server reachability issue

For LWSSSCS_UNREACHABLE state, the additional ord arg has b0 set if the
reason for the unreachability is because the DNS server itself was not
reachable (implying either DNS server is wrongly set, or is not reachable
due to not having connectivity through to it)